Component

Simple calculator is a mobile application used for making mathematical calculations. This application has an arranged design where functions and numbers are perfectly positioned in the keyboard.

Proposal

By using this app to make some calculations, I notice that I can not add negative and positive to the numbers I press on this calculator.
My suggestions with the negative and positive sign of the user can indicate which ones are negative and positive

Mockups / Examples

• Display calculator for now
  

• Display calculator if my ideas implementation
  

Benefits

The usefulness or more precise benefit of my idea is, all the usual calculator users, to be able to mark numbers with negative and positive numbers.